Method for addressing misalignment of leds on a printed circuit board

ABSTRACT

LEDs for an illumination system may be mounted on a PCB. The PCB may be provided with alignment features such as oversized holes for connection to a support surface. Using optical sensing of the position of the mounted LEDs, the space made available by the alignment features may be reduced and aligned to create modified alignment features. The modified alignment features may be created by adding a modifying component and aligned based on the sensed positions of the mounted LEDs. The positioning of the modifying component may offset misalignment of the LEDs with the PCB. An opening in the modified alignment feature may receive a bolt or alignment pin for connection to the support surface. The support surface may be aligned with the secondary optics, resulting in the LEDs being aligned with the secondary optics irrespective of misalignment of the LEDs with respect to the PCB.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/220,759, filed Dec. 14, 2018, which is a continuation of U.S.application Ser. No. 15/849,384, filed Dec. 20, 2017, which claimspriority to U.S. Provisional Patent Application No. 62/437,593 filed onDec. 21, 2016. U.S. application Ser. No. 16/220,759, U.S. applicationSer. No. 15/849,384, and U.S. Provisional Patent Application No.62/437,593 are incorporated by reference as if fully set forth herein.

BACKGROUND

Light emitting diodes (LEDs) are typically mounted on a printed circuitboard (PCB), and the PCB is mounted on a support surface such as a heatsink or secondary optics. A PCB may typically include mounting holes orother features that enable the PCB to be aligned and mounted to asupport surface.

Misalignment of the LEDs on the PCB can occur due to various processtolerances. Such misalignments can cause sub-optimal operationalconditions as the light emitted from the LEDs may not optimally orefficiently reach secondary optics.

SUMMARY

The following description includes a method for forming an illuminationsystem. A printed circuit board (PCB) with one or more alignmentfeatures for aligning the circuit board with a support surface may beprovided. One or more light emitting diodes (LEDs) may be mounted on thePCB. A position of the one or more LEDs mounted on the PCB may beoptically sensed and the one or more alignment features on the PCB maybe modified based on the optically sensed position of the one or moreLEDs. As a result, one or more modified alignment features may be formedon the PCB. The one or more modified alignment features may be used toalign the PCB with secondary optics such that any misalignment of theLEDs on the PCB is offset by the modifications to the one or morealignment features on the printed circuit board.

The following description also includes an illumination system. A PCBmay have one or more alignment features for aligning the PCB with asupport surface. One or more LEDs may be mounted on the PCB and amodifying piece may be affixed to the one or more alignment features onthe PCB that reduces the size of the one or more alignment features. Asa result, one or more modified alignment features may be formed foroffsetting any misalignment of the LEDs relative to the PCB. Secondaryoptics may be coupled to the PCB using the one or more modifiedalignment features to align the secondary optics to the PCB.

The following description includes a method for forming anotherillumination system. A printed circuit board (PCB) with one or morealignment features for aligning the circuit board with a support surfacemay be provided. One or more light emitting diodes (LEDs) may be mountedon the PCB via solder pads on the PCB metal interconnection pattern. Aposition of the metal interconnection pattern may be optically sensedand the one or more alignment features on the PCB may be modified basedon the optically sensed position of the metal interconnection pattern.As a result, one or more modified alignment features may be formed onthe PCB. The one or more modified alignment features may be used toalign the PCB with secondary optics such that any misalignment of themetal interconnection pattern on the PCB is offset by the modificationsto the one or more alignment features on the printed circuit board.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a cross-sectional view of a PCB having enlarged mountingholes formed in it;

FIG. 1B is a top view of the PCB of FIG. 1A;

FIG. 2A is a cross-sectional view of the PCB of FIG. 1A having a metalfilm deposited around the mounting holes;

FIG. 2B is a top view of the PCB of FIG. 2A;

FIG. 3A is a cross-sectional view of the PCB of FIG. 2A having an arrayof LEDs mounted on it, where the LEDs are aligned with any fiducial onthe PCB;

FIG. 3B is a top view of the PCB of FIG. 3A;

FIG. 4A is a cross-sectional view of the PCB of FIG. 3A, where the LEDsthemselves are used as a fiducial for positioning a metal ring over themounting holes in the PCB, where the metal ring has a center holesmaller than the mounting holes and the metal ring is welded to themetal film;

FIG. 4B is a top view of the PCB of FIG. 4A;

FIG. 4C is a cross-sectional view of a PCB, where the LEDs themselvesare used as a fiducial for positioning a filling proximate to themounting holes in the PCB, where the filling has a center hole smallerthan the mounting holes;

FIG. 4D is a top view of the PCB of FIG. 4C;

FIG. 5 is a cross-sectional view of the PCB of FIG. 4A being mounted ona support surface, where secondary optics are aligned with the supportsurface in a headlight module of an automobile and the center holes ofthe metal rings are used to position the PCB with respect to the supportsurface; and

FIG. 6 is a flowchart of the method used to fabricate the headlightmodule of FIG. 5.

DETAILED DESCRIPTION

Examples of different light emitting diode (“LED”) implementations willbe described more fully hereinafter with reference to the accompanyingdrawings. These examples are not mutually exclusive, and features foundin one example can be combined with features found in one or more otherexamples to achieve additional implementations. Accordingly, it will beunderstood that the examples shown in the accompanying drawings areprovided for illustrative purposes only and they are not intended tolimit the disclosure in any way. Like numbers refer to like elementsthroughout.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present invention. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present. Itwill also be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. It will be understood that these terms areintended to encompass different orientations of the element in additionto any orientation depicted in the figures.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer or region to another element, layer or region asillustrated in the figures. It will be understood that these terms areintended to encompass different orientations of the device in additionto the orientation depicted in the figures.

The subject matter disclosed herein may be used in a wide variety ofapplications including any applicable LED device, array, system, or thelike. Examples provided herein recite automobile headlights simply forillustrative purposes. The techniques disclosed herein including analignment technique places an LED light source at a precise locationrelative to secondary optics, such as lens in a module, for optimal beamcharacteristics. Additional example applications include, but are notlimited to, camera lighting, street lighting, television lighting, solarlighting, plant lighting, consumer goods lighting, or the like.

Conventional techniques to attach LEDs onto a PCB can result inmisalignment of the LEDs on the PCB due to any number of reasons. Forexample, misalignment may occur in the X and Y directions due to processtolerances. Such misalignments may be in the range of 100 microns orgreater. Further, such misalignment of the LEDs on the PCB gets added toany misalignment of the PCB on the support surface. In an automobileheadlight application, for example, such cumulative misalignments resultin non-ideal headlight beam characteristics.

According to the disclosed subject matter, LEDs for an illuminationsystem may be mounted on a PCB and the PCB may be mounted on a supportsurface by, for example, nuts or screws which traverse through or areattached to the PCB and support surface. Any other mounting techniquecan be used that enables the PCB to be aligned with the support surface.The support surface and secondary optics may be part of a headlightmodule for an automobile. The secondary optics, such as a lens used fora headlight in an automobile, may operate optimally when preciselypositioned relative to the LEDs mounted on a PCB.

As disclosed herein, a PCB may include alignment features such asmounting or alignment holes. These alignment features may be larger thancorresponding holes or alignment pins in a support surface. An areasurrounding the alignment features may be coated with a metal film whichcan be used for attaching a modifying component, such as a metal ring,to generate a modified alignment feature, such as a smaller opening,aligned based on a position of LEDs. For clarity, an alignment featureor modified alignment feature refers to a hole or space through which acomponent used to mount a PCB to a support surface, such as a bolt orpin, can be placed.

The LEDs may be mounted on the PCB using any applicable technique suchas by soldering or ultrasonic welding and may be positioned using afiducial on the PCB. The LEDs may be mounted to the PCB by beingattached to solder pads that are arranged in a metal interconnectionpattern on the PCB. A fiducial may be any type of reference. Forexample, a fiducial may be a hole or mark on the PCB, or may be theshape of the PCB itself. During the mounting, there may be inherentmisalignment of the LEDs on the PCB due to process tolerances andmovements of the LEDs during the mounting process.

A modified alignment feature may be created by a modifying component,such as a metal ring, with an opening that is smaller than the alignmentfeature (e.g., the mounting holes in a PCB). The modifying component maybe optically aligned based on the position of the LEDs and positionedover a metal film deposited on the PCB and surrounding the PCB'smounting holes. The modifying component may be welded in place to themetal film by, for example, using a laser. Notably, the modifiedalignment feature corresponds to the opening of the modifying component,once it is attached to the metal film on the PCB. Based on the alignmentwith the LEDs, the smaller opening in the modifying component may beprecisely positioned for mounting the PCB on a support surface such thatany misalignment of the LEDs on the PCB are offset by the positioning ofthe smaller opening. The support surface may be a heat sink or,alternatively, the support surface may be a surface of the secondaryoptics in an illumination system. The smaller opening in the modifyingcomponent may be the same size as a screw hole or alignment pin in asupport surface such that the positioning of the PCB will be precise,allowing the LEDs to align with secondary optics despite misalignment ofthe LEDs on the PCB.

According to the disclosed subject matter, an arrangement of LEDs may beprecisely aligned with secondary optics to emit an optimized beamemission. Secondary optics may be any applicable optics that existoutside of an LED package such as reflector cavities, automobileheadlights, camera lenses, Fresnel lenses, pillow lenses and the like.Such an optimal alignment may result in an alignment tolerance of lessthan 100 microns. By precisely aligning the PCB with a support surfaceand the secondary optics, based on the location of LEDs, an illuminationsystem may exhibit its target characteristics.

FIG. 1A shows a cross-sectional view of a printed circuit board (PCB) 10having alignment features such as oversized mounting holes 12 formed init. The PCB 10 may be made from any applicable material including, butnot limited to, aluminums, laminates, resin impregnated cloths, copper,or the like. The mounting holes 12 may be formed via any applicablemanner such as by stamping or drilling. The mounting holes 12 may bespaced such that they can approximately be in alignment with mountingholes or alignment pins in a support surface (not shown in FIG. 1A). Themounting holes 12 may have a diameter that is wider than the mountingholes or alignment pins in the support surface (not shown in FIG. 1A).The PCB 10 may be a metal core with metal traces on its top surfacealong with solder pads, as shown in FIG. 1B, for connection to the LEDsand arranged in a metal interconnect pattern. The PCB 10 may have powersupply terminals that are connected to wires via a suitable connector.In one example, the PCB may be a square with sides having a length of 5cm.

FIG. 1B shows a top view of the PCB 10 of FIG. 1A. As shown, themounting holes 12 on the PCB 10 are positioned such that the PCB 10material surrounds the mounting holes 12. Although FIG. 1A and FIG. 1Bshow a rectangular PCB 10 and circular mounting holes 12, it will beunderstood that the PCB 10 may be any applicable shape and may be basedon the application associated with the PCB 10. Similarly, the mountingholes 12 may be any shape. For example, the mounting holes 12 may be anon-circular shape. Solder pads 11 may be attached to the PCB 10 usingany applicable application material such as an adhesive or may besoldered onto the PCB 10.

FIG. 2A shows a metal film 14 on the PCB 10 deposited around themounting holes 12. The metal film 14 may be Kovar™, which is anickel-cobalt ferrous alloy. Alternatively, the metal film 14 may bemade in part or as whole of metals, such as copper, nickel, gold, andalloys, or the like. The metal film 14 may be welded, soldered or gluedto a metal ring, as disclosed herein. The metal film 14 may be depositedusing any applicable process such as screen-printing or the like. Asshown, the metal film 14 may have a center opening 13 substantiallyequal in size as the mounting holes 12 in the PCB 10. The metal film 14may be a pre-formed washer and may be affixed to the PCB 10, such thatthe center opening 14 of the washer is approximately the size of themounting holes 12 in the PCB 10.

FIG. 2B is a top view of the PCB 10 of FIG. 2A. As shown, the metal film14 is placed on the PCB 10 such that a center opening 13 in the metalfilm 14 is aligned with the mounting holes 12. Although FIG. 2B shows acircular opening 13 in metal film 14, it will be understood that thecenter opening 13 in metal film 14 may not be circular and maycorrespond to the shape of a mounting hole 12. Solder pads 11 may beattached to the PCB 10 and arranged in a metal interconnect pattern thatfacilitates electronic connections of LEDs placed on the solder pads toelectrical components.

FIG. 3A illustrates an array of LEDs 19 including individual LEDs 18soldered or welded to the solder pads 11 on the surface of the PCB 10.The array of LEDs 19 may be positioned onto the solder pads 11 on thesurface of the PCB 10 using a programmed mounting tool that aligns eachLED 18 to its associated mounting pad and solders or welds theelectrodes of the LEDs 18 to the respective solder pads 11 on thesurface of the PCB 10. The LEDs 18 may be optically aligned with anytype of fiducial on the PCB 10, such as marks, holes, the solder padsthemselves, the shape of the PCB 10, or the like. The aligning tool mayuse physical contact with a fiducial, such as a corner of the PCB 10, toalign the LEDs 18. Such an alignment process may have a tolerance of 100microns, which adds to the alignment tolerances of other alignments inthe system. Additionally, the LEDs 18 may shift during a solder reflowprocess. Additionally, the solder pads 11 on the PCB 10 may not beprecisely aligned with any fiducials on the PCB 10, which may add to theLEDs' misalignment on the PCB 10. Such a solder pad misalignment may be,for example, +/−125 microns. Based on the number and frequency ofmisalignments, the LEDs 18 may have a position tolerance in excess of+/−200 microns on the PCB 10. The alignment tool may align the LEDs 18using the same fiducial. Accordingly, it should be noted that thealignment of the LEDs 18 with respect to the each other may be accurateas a result of the alignment tool aligning the LEDs 18 to the samefiducial such that all the LEDs 18 are treated the same, relatively.

FIG. 3B shows a top view of the PCB 10 of FIG. 3A. Although arectangular array 19 of LEDs 18 is shown, the array may be any shape.For example, the array may be circular or other shape based on theapplication.

As further disclosed herein, the alignment features (e.g., holes) in thePCB may be reduced in size by using a modifying component to createmodified alignment features that are smaller than the alignmentfeatures. The position of the modified alignment features may bedetermined by using one or more LEDs as a fiducial, such that theposition of the modified alignment features enables precise alignment ofthe PCB with a support surface. The modifying component may be a metalring as shown in FIG. 4A and FIG. 4B, a filling as shown in FIGS. 4C and4D, or the like.

FIG. 4A shows an optical sensor 22 configured to sense the position ofone or more LEDs 18 such that the one or more LEDs 18 act as a fiducialfor the alignment of a modified component such as a pre-formed metalring 24 (e.g., a washer) over the metal film 14. As an example, an LED18A may be used as a fiducial such that the optical sensor 22 may aligna metal ring 24 based on the position of the LED 18A. More specifically,as an example, the metal ring 24 may be aligned based on the location ofa corner of the LED 18A. As another example, an LED 18A and an LED 18Bmay together be used as a fiducial such that optical sensor 22 may aligna metal ring 24 based on the position of LEDs A and B. As a specificexample, the median point between corners of LED 18A and LED 18B may actas a fiducial to align metal ring 24.

The metal ring 24 may contain a center hole 26 that is smaller than themounting holes 12 in the PCB 10. As stated herein, the center hole 26may be aligned based on one or more of the LEDs 18 instead of a fiducialon the PCB 10. Thus, any misalignment of the LEDs 18 with respect to thePCB 10 may be rendered irrelevant as the alignment of metal ring 24 isbased only on the LEDs. The reason the misalignment of the LEDs 18 withrespect to the PCB 10 may be rendered irrelevant is because thetolerance conditions for an illumination system may rely on aligning theLEDs 18 with a support surface, and not the PCB with a support surface.Accordingly, the misalignment of LEDs 18 on PCB 10 would be relevantonly if the position of the PCB 10 was then aligned with a supportsurface. By aligning the metal ring 24 based on the LEDs 18, anymisalignment of the LEDs 18 with the PCB 10 would be offset. In oneimplementation, the center point of the metal ring 24 is opticallyaligned with the furthest LED 18A or 18B, as it may be assumed that thefurthest LED is the most misaligned with respect to the mounting hole12.

The metal ring 24 may be welded to the metal film 14 by heating themetal ring 24 with a laser to mitigate shifting of the metal ring 24.The metal ring 24 may have a bottom surface that can easily weld to themetal film 14, such as Kovar™ with a Ni coating.

The center hole 26 in the metal ring 24 may be approximately the samediameter as a mounting hole or alignment pin in a support surface, asfurther described herein. As shown in FIGS. 4A and 4B, the center hole26 of the metal ring 24 may not align exactly with the center of themounting hole 12 in the PCB 10, such that the offset is approximatelyequal to the misalignment of the LEDs 18 with respect to the PCB 10 Thepositional accuracy of the metal ring 24 may be +/−25 microns.

FIG. 4B is a top view of the PCB of FIG. 4A which includes a modifyingcomponent, metal ring 24. As shown, the center hole 26 of the metal ring24 does not align with the center of the mounting hole 12 in the PCB 10.

It should be noted that a metal film 14 need not be used such that themetal ring 24 may be directly affixed to the PCB 10 via tape, solder,epoxy, or other means. However, use of the metal film 14 may provide anefficient option for some applications as a result of the raised filmand/or as a result of the material used for the metal film 14.

FIG. 4C shows an optical sensor 22 configured to sense the position ofone or more LEDs 18 such that the one or more LEDs 18 act as a fiducialfor the alignment of a modifying component such as adjustment fill 27.As an example, an LED 18A may be used as a fiducial such that theoptical sensor 22 may align adjustment fill 27 based on the position ofthe LED 18A. More specifically, as an example, the adjustment fill 27may be aligned based on the location of a corner of the LED 18A. Asanother example, LED 18A and an LED 18B, as shown in FIG. 4C and FIG. 4Dmay together be used as a fiducial such that optical sensor 22 may alignan adjustment fill 27 based on the position of LEDs A and B. As anexample, the median point between corners of LED 18A and LED 18B may actas a fiducial to adjustment fill 27.

The adjustment fill 27 may create a center hole 28 that is smaller thanthe mounting hole 12 in the PCB 10. As stated herein, the center hole 28may be aligned based on one or more of the LEDs 18 instead of a fiducialon the PCB 10. Thus, any misalignment of the LEDs 18 with respect to thePCB 10 may be rendered irrelevant as the alignment of adjustment fill 27is based only on the LEDs. The reason the misalignment of the LEDs 18with respect to the PCB 10 may be rendered irrelevant is because thetolerance conditions for an illumination system may rely on aligning theLEDs 18 with a support surface, and not the PCB with a support surface.Accordingly, the misalignment of LEDs 18 on PCB 10 would be relevantonly if the position of the PCB 10 was then aligned with a supportsurface. By aligning the adjustment fill 27 based on the LEDs 18, anymisalignment of the LEDs 18 with the PCB 10 would be offset. In oneimplementation, the center point of the adjustment fill 27 is opticallyaligned with the furthest LED 18A or 18B, as it may be assumed that thefurthest LED is the most misaligned with respect to the mounting hole12.

The adjustment fill 27 may be deposited onto the metal film 14 andattached onto the metal film 14 via any applicable technique such aswelding, using an adhesive, soldering, or the like. The center hole 28created by the adjustment fill 27 may be approximately the same diameteras a mounting hole or alignment pin in a support surface, as furtherdescribed herein. As shown in FIGS. 4C and 4D, the center hole 28created by the adjustment fill 27 may not align exactly with the centerof the mounting hole 12 in the PCB 10, such that the offset isapproximately equal to the misalignment of the LEDs 18 with respect tothe PCB 10 The positional accuracy of the adjustment fill 27 may be+/−25 microns.

FIG. 4D is a top view of the PCB of FIG. 4A which includes a modifyingcomponent, adjustment fill 27. As shown, the center hole 28 of theadjustment fill 27 reduces the space made available by mounting hole 12in the PCB 10.

It should be noted that a metal film 14 need not be used such that theadjustment fill 27 may be directly affixed to the PCB 10 via tape,solder, epoxy, or other means. As an example, the adjustment fill 27 maybe attached directly within mounting hole 12. However, use of the metalfilm 14 may provide an efficient option for some applications as aresult of the advantages provided by the easy of application to themetal film 14 or of the material used for the metal film 14.

According to an implementation, LEDs 18 are may be precisely positionedon their respective solder pads on the PCB 10. The solder pads may bearranged in a metal interconnect pattern that enables LEDs 18 placed onthe solder pads to be connected to electronic components. In such aconfiguration, the fiducial for positioning a modifying component suchas the metal ring 24 or adjustment fill 27 may be the solder pads forthe PCB 10 or any other feature of the solder pad pattern. Because theLEDs 18 in this configuration are precisely positioned on the respectivesolder pads, using the solder pads as the fiducial for the modifiedalignment feature can provide the same result as aligning the modifiedalignment feature based on the LEDs 18. Accordingly, in such a preciselypositioned LED configuration, aligning the modified alignment featurebased on the solder pads may render any misalignment between the solderpads and PCB 10 irrelevant.

FIG. 5 illustrates an illumination system 34 based on the subject matterdisclosed herein. As an example, the illumination system 34 may aheadlight module. The PCB 10 of FIG. 4A may be mounted on a supportsurface 30 such as a heat sink. The support surface 30 and the secondaryoptics 32 may be attached, connected, or otherwise associated such thataligning an LED array to either the support surface 30 or the secondaryoptics 32 also results in an alignment with the other. The supportsurface 30 and secondary optics 32 may be connected by the housing (notshown) that holds both the support surface 30 and secondary optics 32.Alternately, the support surface 30 may be part of the secondary optics32 or may be connected directly to the secondary optics 32 via aconnector such as via a metal connector, a screw, a clamp, or the like.

The mounting holes 36 in the support surface 30 may have the samediameter as the modified alignment features created by the center holes26 of metal rings 24. It should be noted that the mounting holes 36 maybe alignment pins or tabs or any other alignment feature. A bolt 38,having a rod with a diameter approximately equal to the diameter of themounting holes 36 and center holes 26 of the metal rings 24, may be usedto secure the PCB 10 to the support surface 30. As shown in FIG. 5, thebolt 38 may have a top portion 39 that is larger than the diameter ofthe rod, although such a top portion is not required. A nut 40 may beused for fastening the bolt 38 to the support surface 30. Alternatively,instead of a nut 40, the heat sink mounting holes 36 may be threaded,which may allow the bolt 38 to screw into the mounting holes 36.Alternatively, the bolt 38 may represent a fixed alignment pin extendingfrom the support surface 30 and configured to attach to the PCB 10 viathe metal rings 24. Overall, the support surface 30 may be attached tothe PCB 10 in any manner while maintaining the alignment describedherein.

Accordingly, using the techniques described herein, the LEDs 18 can beprecisely aligned with the support surface 30 and, thus, may preciselyalign with the secondary optics 32 in the X-axis and Y-axis despite anymisalignment of the LEDs 18 relative to the PCB 10.

According to an implementation, the LEDs 18 may be positioned at a focalpoint of the secondary optics 32, and the secondary optics 32 may createa beam with the desired characteristics for a given illumination system.In the example of an automobile headlight system, both headlights of avehicle can be made to have identical beams or slightly different beams.

Although bolt 38 is shown to secure the PCB 10 to support surface 30 inFIG. 5, any applicable securing mechanism to secure the PCB 10 tosupport surface 30 may be used, so long as the position of mounted LEDs18 is used to align the securing mechanism.

As an alternative to using actual LEDs 18 to align modified alignmentfeature, a related fiducial such as one or more tabs, notches, slits, orthe like, that is created or adjusted after the mounting of the LEDs 18to the PCB 10 may be used to align the securing mechanism. Note that theposition of the related fiducial is based on the LEDs 18 such thatalthough the related fiducial may be used to conduct the alignment, thealignment is still based on the LEDs 18. For example, a notch on a PCBside that is used as a fiducial for aligning the PCB to the supportsurface may initially be oversized. After the LEDs are mounted on thePCB, an alignment piece may be welded to the PCB that closes up thenotch slightly to align the narrowed notch to the actual locations ofthe LEDs. The narrowed notch may then be used as the fiducial foraligning the modified alignment feature. The related fiducial may berectangular or any other shape and may be made of metal or any otherapplicable material.

According to an implementation, the support surface may be part of orattached to the secondary optics such that the secondary optics can bedirectly attached to the PCB 10 rather being attached to the PCB 10 viaa heat sink or a housing. The secondary optics 32 may have pins, bolts,or other connection/alignment features that directly attach to the PCB10 via the modified alignment feature (e.g., a metal ring 24 with centerholes 26) on the PCB 10. Therefore, the modified alignment feature maycause the secondary optics to be precisely aligned with the LEDs 18.Notably, the modified alignment feature may allow either a supportsurface/secondary optics combination, as previously discussed, orsecondary optics to align based on the position of the LEDs 18 ratherthan the PCB 10.

FIG. 6 is a flowchart of a process 600 used to fabricate theillumination system of FIG. 5. As shown, at step 50, oversized holes orother alignment features may be formed in a PCB. The holes may becircular or any other applicable shape.

At step 52, a metal film may be formed around the holes in the PCB. Themetal film may facilitate welding components onto the metal film moreefficiently than directly affixing such components onto the PCB.However, it should be noted that a modifying component, as disclosedherein, may be directly affixed to the PCB using applicable measuresthat mitigate shifting of the modifying component.

At step 54, LEDs may be mounted on the PCB using any fiducial on the PCBfor aligning the LEDs with the PCB. Metal traces forming a metalinterconnection pattern on the PCB may interconnect the LEDs and connectthem to power supply terminals. A mounting tool may be used to mount theLEDs onto pads on the PCB.

At step 56, modifying components such as metal rings may be providedthat include a center opening that is smaller than the alignmentfeatures formed in the PCB. The center opening may have the samediameter as a mounting hole or an alignment pin on a support surface.The center points of the modifying components may be positioned based onaligning with the LEDs themselves or, for example, with solder padsarranged in a metal interconnection pattern. As an example, a metal ringmay be aligned with an LED that is furthest away from the metal ring asthat LED may be presumed to be the most misaligned with respect to theoversized hole in the PCB. Solder pads may be arranged in a metalinterconnection pattern and, as disclosed herein, a modifying componentmay be aligned based on the metal interconnection pattern if the LEDsare precisely placed on the solder pads.

At step 58, the metal ring may be welded to the metal film on the PCB bya laser. As disclosed herein, if a metal film is not used, then amodifying component, such as a metal ring, may be affixed directly tothe PCB.

At step 60, the PCB may be attached to a support surface using the metalring's center openings for alignment, such as by inserting a bolt oralignment pin through the center opening. The bolt may be fastened usinga nut or may be screwed into the housing of, for example, the supportsurface.

At step 62, secondary optics such as lenses may be aligned with thesupport surface. The alignment may be caused by the support surface andsecondary optics being contained in the same housing. Alternatively, thealignment of the secondary optics with the support surface may be aresult of attaching the secondary optics to the support surface via anyapplicable mounting techniques.

Notably, based on the techniques disclosed herein, LEDs on a PCB may beXY aligned with respect to the secondary optics in a high precisionmanner, such that the misalignment is within a +/−25 micron range Suchan alignment may result in optimal beam characteristics.

While particular embodiments or implementations of the present inventionhave been shown and described, it will be obvious to those skilled inthe art that changes and modifications may be made without departingfrom this invention in its broader aspects and, therefore, the appendedclaims are to encompass within their scope all such changes andmodifications as fall within the true spirit and scope of thisinvention.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs).

What is claimed is:
 1. A device comprising: a circuit board; a firstopening in the circuit board; an LED on the circuit board; and a metalmember mechanically coupled to the circuit board over the first opening,the metal member comprising a second opening smaller than the firstopening, the metal member located on the circuit board with a center ofthe second opening offset relative to a center of the first openingbased on a location of at least a portion of the LED on the circuitboard.
 2. The device of claim 1, further comprising a support comprisinga third opening approximately equal in size to the second opening. 3.The device of claim 2, further comprising a connector member at leastpartially in the first opening, the second opening and the thirdopening, the connector member having a cross section approximately equalin size to the second opening and the third opening.
 4. The device ofclaim 1, further comprising a secondary optic comprising a fourthopening approximately equal in size to the second opening.
 5. The deviceof claim 4, further comprising a connector member at least partially inthe first opening, the second opening and the fourth opening, theconnector member having a cross section approximately equal in size tothe second opening and the fourth opening.
 6. The device of claim 1,wherein the LED comprises a plurality of LEDs, and the metal member islocated on the circuit board with the center of the second openingoffset relative to the center of the first opening based on a locationof at least a portion of at least one of the plurality of LEDs on thecircuit board.
 7. The device of claim 1, wherein the first openingcomprises a plurality of first openings and the metal member comprises aplurality of metal members.
 8. The device of claim 1, further comprisinga metal film on the circuit board surrounding the first opening, themetal member being mechanically coupled to the circuit board via themetal film.
 9. The device of claim 1, wherein the metal member has acircular shape and the first opening has a circular shape.
 10. Thedevice of claim 1, wherein the metal member has a non-circular shape andthe first opening has a non-circular shape.
 11. A device comprising: acircuit board; a first opening in the circuit board; an LED on thecircuit board; a fill material at least partially in the first openingand forming a second opening smaller than the first opening and at leastpartially within the first opening, a center of the second opening beingoffset relative to a center of the first opening based on a location ofat least a portion of the LED on the circuit board.
 12. The device ofclaim 11, further comprising a support comprising a third openingapproximately equal in size the second opening.
 13. The device of claim12, further comprising a connector member at least partially in thesecond opening and the third opening, the connector member having across section approximately equal in size to the second opening and thethird opening.
 14. The device of claim 11, further comprising asecondary optic comprising a fourth opening approximately equal in sizeto the second opening.
 15. The device of claim 14, further comprising aconnector member at least partially in the second opening and the fourthopening, the connector member having a cross section approximately equalin size to the fourth opening and the second opening.
 16. The device ofclaim 11, wherein the LED comprises a plurality of LEDs, and the centerof the second opening is offset relative to the center of the firstopening based on a location of at least a portion of at least one of theplurality of LEDs on the circuit board.
 17. The device of claim 11,wherein the first opening comprises a plurality of first openings andthe fill material comprises a plurality of fill materials.
 18. Thedevice of claim 11, further comprising a metal film on the circuit boardsurrounding the first opening, the fill material at least partiallydisposed in a fifth opening in the metal film.
 19. A method comprising:obtaining a circuit board defining an opening and having a least one LEDmounted thereon; obtaining an alignment member defining an openingsmaller than the opening in the circuit board; determining a location ofat least a portion of the at least one LED mounted on the circuit board;determining a placement location for the alignment member based on thedetermined location of the at least the portion of the at least one LEDmounted on the circuit board, the placement location being an offsetbetween a center of the opening in the circuit board and a center of theopening in the alignment member; and mechanically coupling the alignmentmember to the circuit board at the determined placement location. 20.The method of claim 19, wherein the mechanically coupling comprisesmechanically coupling the alignment member at least one of to a topsurface of the circuit board or at least partially within the opening inthe circuit board.